Book Image

Mastering Microservices with Java - Third Edition

By : Sourabh Sharma
Book Image

Mastering Microservices with Java - Third Edition

By: Sourabh Sharma

Overview of this book

Microservices are key to designing scalable, easy-to-maintain applications. This latest edition of Mastering Microservices with Java, works on Java 11. It covers a wide range of exciting new developments in the world of microservices, including microservices patterns, interprocess communication with gRPC, and service orchestration. This book will help you understand how to implement microservice-based systems from scratch. You'll start off by understanding the core concepts and framework, before focusing on the high-level design of large software projects. You'll then use Spring Security to secure microservices and test them effectively using REST Java clients and other tools. You will also gain experience of using the Netflix OSS suite, comprising the API Gateway, service discovery and registration, and Circuit Breaker. Additionally, you'll be introduced to the best patterns, practices, and common principles of microservice design that will help you to understand how to troubleshoot and debug the issues faced during development. By the end of this book, you'll have learned how to build smaller, lighter, and faster services that can be implemented easily in a production environment.
Table of Contents (22 chapters)
Free Chapter
1
Section 1: Fundamentals
6
Section 2: Microservice Patterns, Security, and UI
11
Section 3: Inter-Process Communication
15
Section 4: Common Problems and Best Practices

Circuit breaker

In general terms, a circuit breaker is:

An automatic device for stopping the flow of current in an electrical circuit, as a safety measure.

The same concept is used for microservice development, known as the circuit breaker design pattern. It tracks the availability of external services such as Eureka Server, API services such as restaurant-service, and so on, and prevents service consumers from performing any action on any service that is not available.

It is another important aspect of microservice architecture, a safety measure (a failsafe mechanism) for when the service does not respond to a call made by the service consumer—a circuit breaker.

We'll use Netflix Hystrix as a circuit breaker. It calls the internal fallback method in the service consumer when failures occur (for example, due to a communication error or timeout). Hystrix code gets executed...